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Biomedical subjects

J Lewis

Publications and source records attributed to J Lewis.

At least 235 records · Page 13Linked to original sources
PubMed1994

Requiring elderly patients to give signed consent for influenza vaccine. Does it affect acceptance?

This study aimed to determine whether requiring signed consent before influenza vaccination affected vaccine acceptance by elderly patients. Previous influenza vaccination was determined by chart review. All subjects agreed to sign the consent. Requiring signed consent did not affect influenza vaccine acceptance in this population. Mailed reminder letters and information packages in patients' charts significantly increased vaccination rates.

Aged↗
PubMed1993

Stress-induced alignment of actin filaments and the mechanics of cytogel.

Experimental evidence suggests that anisotropic stress induces alignment of intracellular actin filaments. We develop a model for this phenomenon, which includes a parameter reflecting the sensitivity of the microfilament network to changes in the stress field. When applied to a uniform cell sheet at rest, the model predicts that for sufficiently large values of the sensitivity parameter, all the actin filaments will spontaneously align in a single direction. Stress alignment can also be caused by a change in external conditions, and as an example of this we apply our model to the initial response of embryonic epidermis to wounding. Our solutions in this case are able to reflect the actin cable that has been found at the wound edge in recent experiments; the cable consists of microfilaments aligned with stress at the wound boundary of the epithelium. These applications suggest that stress-induced alignment of actin filaments could play a key role in some biological systems. This is the first attempt to include the alignment phenomenon in a mechanical model of cytogel.

Actins↗
PubMed1993

Percutaneous gastrojejunostomy versus Nissen fundoplication for enteral feeding of the neurologically impaired child with gastroesophageal reflux.

To determine the optimal method of providing enteral feeding to neurologically impaired children with gastroesophageal reflux, Nissen fundoplication with simultaneous gastrostomy tube placement (NGT) was compared with anterograde percutaneous gastrojejunostomy (APGJ), a nonsurgical procedure performed under fluoroscopic guidance. The records of 112 neurologically impaired children with gastroesophageal reflux were retrospectively reviewed; 68 had undergone NGT and 44 APGJ. Follow-up data were available for 45 NGT patients (mean age, 6.4 years) and 34 APGJ patients (mean age, 7.9 years). Mean follow-up was 1.8 years in the NGT group and 2.5 years in the APGJ group. Complications resulting from either procedure were classified either as major, which included treatment failures or morbidity resulting in prolonged hospitalization, or as minor, those requiring outpatient treatment only or not directly caused by the procedure. The NGT group had a significantly higher incidence of major complications in comparison with the APGJ group (33.3% vs 11.8%, p < 0.05). Ten patients (22.2%) in the NGT group required reoperation for complications; six required a second NGT for wrap hernia, failure, and continued gastroesophageal reflux. Two patients (5.9%) in the APGJ group required surgery for complications; one of these eventually required an NGT, and the other had an intussusception that necessitated a small-bowel resection. Minor complications were more common in the APGJ group than in the NGT group (44.1% vs 6.6%); the majority of complications were related to the jejunostomy tube. Premature replacement or reinsertion of the jejunostomy tube was necessary in 14 APGJ patients (32%). The mortality rate was 8.8% in the NGT group and 5.9% in the APGJ group (p = not significant). No death occurred within 30 days of either procedure. We conclude that APGJ is a safe alternative method for feeding the neurologically impaired child with gastroesophageal reflux.

Adolescent↗
PubMed1993

Anatomy of a trial: a historical view of the Monroe inactivated hepatitis A protective efficacy trial.

The performance of vaccine protective efficacy trials is often more complex than reports of final results suggest. The current article reviews the background, planning and preparations for the Monroe, NY, protective efficacy trial of a formalin-inactivated, alum-adjuvanted hepatitis A vaccine (VAQTA, manufactured by Merck Research Laboratories). The vaccine trial was carried out at Kiryas Joel, a Hasidic Jewish community which had experienced numerous annual outbreaks in a local environment with similarities to day-care centers. Careful communication, and cooperation of community leadership, a flexible technical resource team, and knowledge of an epidemic already ongoing in a sister community whose members were due to arrive for summer holidays, permitted rapid and efficient completion of the trial with a striking demonstration of protection after a single vaccine dose.

Clinical Protocols↗
PubMed1993

The energy and nutrient intakes of different types of vegetarian: a case for supplements?

Vegetarians of three types were studied in Greater London: thirty-four meat-avoiders, fifty-two lacto-ovo-vegetarians, and thirty-eight vegans. Weighed dietary intake measures were made over 3 d. Cereals were the mainstay of the diet, supplemented by dairy products (demi-vegetarians and lacto-ovo-vegetarians), vegetables and fruit, and soya-bean products (vegans). Many vegans progressed by stages to complete avoidance of animal foods; some had retreated, but most were highly committed. Demi-vegetarians were the least involved in a 'vegetarian lifestyle'. All groups had mean energy intakes close to the current dietary reference values (DRV), with adequate protein intakes. Only vegans had fat intakes close to current recommendations; all groups had high dietary polyunsaturated:saturated fatty acid ratios. Mean intakes of all micronutrients studied for demi- and lacto-ovo-vegetarians met the UK DRV. Intakes of iodine, riboflavin, and vitamin B12 for vegans were below DRV; more than half considered their diets supplied all necessary vitamins. About 25% took some type of dietary supplement during the survey. The impact of low I intakes should be further studied, and it is recommended that 'new' vegetarians and vegans should use appropriate dietary supplements.

Adult↗
PubMed1993

Prevalence of self-medication with antibiotics among patients attending a clinic for treatment of sexually transmitted diseases.

To ascertain the prevalence of self-medication with antimicrobial agents among patients attending a clinic for treatment of sexually transmitted diseases (STDs), we administered a questionnaire to and collected a urine specimen for antimicrobial testing from 551 patients before treatment. We defined self-medication as an antimicrobial agent taken on the patient's own initiative by self-report during the week before the visit to the clinic or a positive urine assay for antimicrobial agents at the time of the clinic visit. We tested urine for the presence of antimicrobial agents by a disk diffusion method using Sarcina lutea as the test organism. A total of 75 (14%) of the 551 participants were self-medicators: 19 reported antimicrobial use and had a positive urine test, 27 reported antimicrobial use but had a negative urine test, and 29 denied antimicrobial use but had a positive urine test. Thus, 29 (60%) of the 48 patients with antimicrobial agents detected in their urine at the time of the clinic visit denied self-medication. Self-medicators acquired their antibiotics either from their medicine cabinet (44%) or from a family member or friend (56%). Self-medication was associated with self-report of prior use of unprescribed antimicrobial agents (P < .0001). We concluded that use of unprescribed antimicrobial agents (usually beta-lactam agents or tetracyclines) among STD clinic attendees in our study was common and that self-reporting was not a reliable method of screening for self-medicators.

Adult↗
PubMed1993

Acute fatty liver of pregnancy after exposure to toluene. A case report.

We describe a patient in whom acute fatty liver of pregnancy developed after long-term toluene exposure. Acute fatty liver of pregnancy was documented by a liver biopsy specimen stained with oil red O and observed under electron microscopy. Although the mother did well, she gave birth to a stillborn whose autopsy showed visceral congestion and placental infarction. This case raises the hypothesis of a possible relationship between toluene exposure and acute fatty liver of pregnancy.

Acute Disease↗
PubMed1993

Safety, tolerability and immunogenicity of a formalin-inactivated hepatitis A vaccine (VAQTA) in rural Kentucky children.

This study evaluated the immunogenicity and safety/tolerability profile of an investigational formalin-inactivated hepatitis A virus vaccine (VAQTA; Merck Research Laboratories) in 150 seronegative healthy children, 4 to 12 years old. The vaccine was derived from virus grown in infected MRC-5 cells in either roller bottles or Nunc cell factories (Nunc, Denmark). Subjects were vaccinated intramuscularly in a two dose regimen initially and at 24 weeks: Group A (n = 50) with a 12-unit dose from a roller bottle lot; Group B (n = 50) with a 25-unit dose from another roller bottle lot; and Group C (n = 50) with a 25-unit dose from a Nunc cell lot. Sera for anti-hepatitis A virus antibodies were drawn 3 weeks before vaccination and 4, 24 and 28 weeks after the first dose. Seroconversion from < 10 mIU/ml to > or = 10 mIU/ml by modified HAVAB (Abbott Laboratories) was observed in 99% of subjects at week 4 and persisted in 100% of subjects at week 28 (4 weeks after the second dose). The ranges of geometric mean titers of anti-HAV for all subjects at weeks 4, 24 and 28 were 31 to 49, 51 to 79 and 7059 to 29,609 mIU/ml, respectively. The 12- and 25-unit dose levels of roller bottle yielded similar geometric mean titers. The rise in geometric mean titers after the booster dose was > 120-fold and was highest in the recipients of the 25-unit Nunc cell lot (P < 0.05 for Group C vs. B).(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1993

Heart rates during competitive orienteering.

This study investigated the heart rate profiles of 16 experienced, competitive orienteers (aged 15-62 years) during three competitive events. Each competitor was assessed over three different types of course which were classified as: fast run (FR), slow run (SR) and highly physical (HP). The results showed that all subjects recorded heart rates that were between 140 and 180 beats min-1 for the majority of each event (irrespective of age or course type). The heart rate data indicated that the activity was largely aerobic but varied in intensity, with phases of strenuous anaerobic work. The type of course was shown significantly (analysis of variance; P < 0.001) to affect the mean heart rate attained by each orienteer (FR = 160, HP = 158, SR = 150 beats min-1), with courses that required more technical skill and hence slower running producing lower mean heart rates; although the general physical demands were similar for all courses. The older orienteers (> 45 years) recorded heart rate profiles that were similar to those of the young orienteers with no correlation being found between age and mean heart rate while exercising.

Adolescent↗
PubMed1993

Evaluation of the Colin STBP-680 at rest and during exercise: an automated blood pressure monitor using R-wave gating.

The application of automated blood pressure measurement during exercise has been limited by inaccuracies introduced by the effects of accompanying motion and noise. We evaluated a newly developed automated blood pressure monitor for measuring exercise blood pressure (Colin STBP-680; Colin, San Antonio, Texas, USA). The STBP-680 uses acoustic transduction with the assistance of the electrocardiogram R-wave to trigger the sampling period for blood pressure measurement. The automated monitor readings were compared with simultaneous technician mercury sphygmomanometric readings in the same arm. Blood pressure was measured in 18 men at rest and during exercise at 40% VO2 peak, (low intensity), 70% VO2 peak (moderate intensity) and VO2 peak (high intensity) on the cycle ergometer. Mean(s.d.) systolic blood pressure difference between the automated monitor and mercury manometer readings at rest and during exercise at low, moderate and high work intensities were 3(0) mmHg, 3(2) mmHg, 1(1) mmHg, and 0(11) mmHg respectively (analysis of variance; P > 0.05). Resting diastolic blood pressure obtained with the STBP-680 was similar to the mercury manometer readings (78(10) versus 81(7) mmHg (P > 0.05). Exercise diastolic pressure at the low level of work intensity was almost identical between the automated monitor and mercury manometer readings (64(8) versus 65(10) mmHg (not significant)). Diastolic blood pressure readings between the STBP-680 and mercury manometer showed a greater difference at the moderate and high workloads (11 mmHg and 9 mmHg, respectively), but this difference was not significant (P > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Surfactant treatment effects on alveolar type II cell morphology in rabbit lungs.

The effects of exogenous surfactant administration on alveolar type II cells and the lung parenchyma were examined in adult rabbits. Natural surfactant was instilled into the left lobe of New Zealand White rabbits while the right lobe served as the control. Four hours post-instillation, the lungs were fixed by vascular perfusion. Surfactant instillation did not change alveolar type II cell size but was associated with a significant reduction in the volume fraction of lamellar bodies in type II cells (20.4% in control lobes compared with 11.9% in surfactant-treated lobes). The size distribution of lamellar body profiles was different in surfactant-treated lobes compared with control lobes, with a significant decrease in lamellar bodies > 0.8 microns in diameter and a twofold increase in lamellar bodies 0.2-0.4 microns in diameter. Composite body profile number was also increased by 87% (P < 0.05) after instillation of surfactant compared with control. Saline instillation decreased lamellar body volume fraction in type II cells but three times less than surfactant instillation. These observations are consistent with a strong stimulus for secretion of endogenous surfactant 4 h after surfactant instillation in normal adult rabbit lungs, whereas the increase in composite bodies is consistent with new lamellar body formation, probably from both de novo synthesized and exogenous natural rabbit surfactant. These observations confirm that the secretory and synthetic processes of alveolar type II cells are significantly affected by exogenous surfactant instillation.

Animals↗
PubMed1993

Alterations in pulmonary surfactant composition and activity after experimental lung transplantation.

Pulmonary surfactant facilitates breathing by reducing the surface tension at the air/liquid interface. We examined the effect of experimental lung transplantation on the phospholipid pool sizes of alveolar surfactant large and small aggregates, the composition of the large aggregates, the surface tension-reducing ability of lipid extract surfactant, and the leakage of serum proteins into the lung. A double-lung block from the donor animal was stored for 2 or 12 h after perfusion with either Euro-Collins solution or University of Wisconsin solution. The right donor lung was lavaged immediately after the storage period to determine the effects of storage on pulmonary surfactant. The left donor lung was transplanted. The recipient animal, containing its own native right lung and the transplanted left lung, was reperfused for 6 h. After the reperfusion period, the transplanted left lung and the native right lung were lavaged. After an ischemic time of 12 h, impaired gas exchange was observed in the transplanted lung as well as the native lung during the 6 h of reperfusion. This impaired gas exchange was associated with several significant changes in pulmonary surfactant: (1) total serum protein in the lung lavage was increased, (2) the small to large surfactant aggregate ratio was increased, (3) sphingomyelin content was increased and phosphatidylglycerol content was decreased in large aggregates, and (4) the surfactant-associated protein A content was decreased in large aggregates. No significant differences were observed between the results obtained with Euro-Collins and University of Wisconsin solutions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗
PubMed1993

B7/CD28 but not LFA-3/CD2 interactions can provide 'third-party' co-stimulation for human T-cell activation.

The requirement for co-stimulation in T-cell activation has become firmly established, whilst the precise identity of the molecules involved remains uncertain. Some of the major co-stimulatory molecules include ICAM-1, LFA-3 and B7. We have investigated the abilities of both LFA-3 and B7 to co-stimulate T-cell proliferation under a number of conditions using transfected Chinese hamster ovary cells. Using anti-CD3 antibodies we observed that B7 but not LFA-3 transfectants were capable of co-stimulating proliferation in purified peripheral blood T cells. In addition, both LFA-3 and B7 could induce proliferation in response to phytohaemagglutinin (PHA) and we obtained additive effects using both B7 and LFA-3 together. Using the superantigen staphylococcal enterotoxin B (SEB), we observed that presentation to purified T cells required the presence of class II-positive transfectants and that sensitivity to antigen was increased approximately 100-fold by the co-transfection of either B7 or LFA-3. However, when co-stimulatory molecules were provided by cells separate from those engaging the T-cell receptor (TcR), only B7 was capable of enhancing proliferation. Kinetic studies which investigated the time dependence for co-stimulation revealed that T cells responding to anti-CD3 antibodies required the B7 co-stimulation within the first few hours, for proliferation to be effective. Our data differentiate between the co-stimulatory abilities of B7 and LFA-3 and support the concept of a pivotal role for B7 in T-cell proliferation.

Antigens, CD↗
PubMed1993

Recombinant vaccinia mucin vector: in vitro analysis of expression of tumor-associated epitopes for antibody and human cytotoxic T-cell recognition.

We have constructed a recombinant vaccinia virus vector that contains human mucin MUC-1 cDNA. Analysis of the recombinant virus isolates showed the tendency of the vaccinia to delete large portions of the mucin tandem repeat region. Epstein-Barr virus (EBV)-immortalized B cell lines from humans and chimpanzees were infected and analyzed for expression of the mucin on the cell surface and the presence of specific epitopes in the tandem repeat region previously shown to be preferentially expressed on tumor cells and recognized by tumor-specific mouse monoclonal antibodies and human cytotoxic T lymphocytes (CTL). We found that this recombinant vector encodes expression of mucin that contains all the epitopes recognized by the antibodies. The tumor-specific epitopes can be further exposed by inhibition of O-linked glycosylation in infected cells. Lack of multiple tandem repeats, however, prevents major histocompatibility complex (MHC)-unrestricted recognition by the CTL of the majority of infected cell lines. Still, we show two examples of an apparent MHC-restricted recognition of vaccinia-encoded mucin that may depend on one or very few rare human lymphocyte antigen (HLA) types capable of presenting the mucin peptides.

Amino Acid Sequence↗
PubMed1993

Eosinophilic perifolliculitis: a variant of autoimmune oophoritis?

We report two middle-aged women with ovarian perifolliculitis consisting mostly of eosinophils. Both had enlarged cystic ovaries that on histological examination showed a perifollicular inflammatory infiltrate consisting of lymphocytes, plasma cells, and large numbers of eosinophils. The inflammatory infiltrate increased in intensity with follicular maturation and appeared to be destroying the theca interna. Circulating antiovarian, antiadrenal, and antithyroid antibodies were negative in both cases. We also compare these cases to lymphoplasmacytic autoimmune oophoritis.

Adult↗